Self-winding electric clock



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E. G. HAMMER. SELF WINDING ELECTRIC CLOCK.

Patented Aug. 25, 1896.

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E. G. HAMMER. SELF WINDING ELECTRIC CLOCK.

No. 566.313. Patented Aug, 25, 1896.

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E. G. HAMMER. SELF WINDING ELECTRIC CLOCK.

No. 566,313. Y Patented Aug. 25, 18

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EMIL G. HAMMER, OF BROOKLYN, NEl/V YORK.

SELF-WINDING ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 566,313, dated August 25, 1896. Application filed January 12, 1891. Serial No. 377,562. (No model.)

To aZZ whom it may concern.

Be it known that I, EMIL G. HAMMER, a citizen of the United States, residing in Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Electric Clocks, of which the following is a specification;

This invention relates to electric clocks or those which are driven or wound by means of electric energy.

This invention is particularly designed as an improvement on the electric clock shown in my Unit-ed States Letters Patent No. 444,433, dated January 13, 1891.

My improved clock measures time through the action of any suitable escapement whichv is driven by a spring that is wound at intervals by means of an electromagnet. The excitation of this magnet is determined by a circuit-closer which closes the circuit at regular intervals of time and is operated by the escapement. The action of the magnet not only rewinds the escapement-spring, but performs the mechanical work incident to the advancing of the hands or other indicating devices of the clock to denote the time.

Figure 1 of the accompanying drawings is a front elevation of my improved clock on a small scale. Fig. 2 is a front elevation of the dial mechanism thereof, partly broken away to show the parts in the rear. Fig. 3 is a front elevation of the driving and time-marking mechanism of the clock, the dial mechanism being removed and the framework omitted. Fig. 4 is a side elevation of the mechanism shown in Fig. 3, but including also the supporting-framework thereof. Fig. 5 is an enlarged front elevation, Fig. 6 a vertical section, and Fig. 7 a plan, of the ratchet mechanism for rewinding the spring. Fig. 8 is an enlarged front elevation of a fragment of Fig. 2, and Fig. 9 is a horizontal section thereof. Fig. 10 shows a part of the mechanism shown in Fig. 3 in connection with circuit-closers for operating secondary electric clocks.

My improved clock will ordinarily be inclosed in an upright casing, such,for example, as shown in Fig. 1. In addition to the usual clock-dial D, having hour and minute hands, the clock-casing is formed in its front with three openings 00 as, through the upper one of which is exposed the number indicatinghours, while through the two lower openings are exposed the numbers indicating minutes. These numbers are marked on three dials A,.B, and 0. (Shown in dotted lines in Fig. 1 and in full lines in Fig. 2, except that in the latter figure they are largely broken away to show the parts behind them.) The dial A is numbered from 0 to 9, and is turned one-tenth of a revolution at the end of each minute. The dial B indicates tens of minutes and is numbered from 0 (blank) to 5, being turned from one number to the next by the dial A while the latter is turning from 9 to O. The dial 0, which indicates hours, is numbered from 1 to l2, and is turned one-twelfth of a revolution by the dial B each time that the latter turns from 5 to blank.

The clock shown in Figs. 1 and 2 has thus two distinct time-indicating devices, one being the hour and minute hands on the dial D and the other being the rotary dials A B C, with the means for rotating them. Both these devices may be used in the same clock, as shown, or either may be omitted.

Referring to Figs. 3 and 4, an electromagnet E, connected in a circuit b'with a battery F, constitutes the motive device through which the entire clock is driven. The armature E of this magnet is mounted on an elbowlever M, having a prolonged lateral arm, on the end of which is carried an antifrictionroller which bears on the long arm of a lever S, the opposite arm of which carries a counterweight w. This counterweight may constitute the retractile device for moving the armature away from the magnet when the latter is demagnetized, or a separate retractile spring 8 may be provided, as shown. time that the circuit is closed the magnet attracts its armature and throws down the long arms of the levels M and S, lifting the counterweight w. The lever S is connected through a rodj with a vibrating arm 70, carrying a pawl Z, which engages the teeth of a ratchet-wheel m, which is kept from turning backward by Each a stop-pawl Z, which is pivoted, Fig. 4, to one of the plates I of the supporting-frame. The ratchet-wheel m is iixed on the front portion of an arbor J, which extends thence rearwardly and is fastened to the inner end of a coiled spring K, which I will. call the escapementspring. The outer end of this spring is fastened directly or indirectly to a gear-wheel L, preferably by inclosing the spring in a drum in the usual manner, fastening its end to the wall of the drum, and forming gear-teeth upon the periphery of the drum. In such case the drum turns loosely on the arbor J, being turned solely by the tension of the coiled spring K. The gear L, to which is thus imparted a tendency to turn in the direct-ion of the arrow in Fig. 3, meshes with a pinion n, also in Fig. 4. This pinion is fixed on a seconds-arbor N, which may carry the secondshand N, Figs. 1 and at. The escapement may be controlled by either a pendulum or a balance-wheel. Thelatter is shown. The arbor N carries a wheel a, which meshes with a pinion on the arbor of the escape-wheel Q, with which engages the anchor R, controlled in the usual way by the balance-wheel P.

The electromagnet E requires, in the construction shown, to be energized once each minute,a-lthou gh otherintervals of time might be selected. To do this, it is necessary to introduce in the circuit Z) some suitable form of circuit-closer which shall be operated at intervals of one minute. Such a circuit-closer is shownin Fig. 3. Two very light levers T T are gently pressed by delicate springs s 8 against stops t t until the lower one is pressed up bya tooth on a cam-disk U, fixed on the seconds-arbor N, whereupon it touches the upper one and they lift together until the tooth passes beyond the end of the lower lever. Both levers are connected in the circuit Z), so that this circuit is normally open, and is closed once each minute when the levers are brought together by the cain-tooth. The closing of the circuit excites the magnet and throws down the long arm of the levers M and S, thereby causing the pawl Z to move down over one tooth of the ratchet-wheel m. Upon the breaking of the circuit the armature is retracted and the lever S is tilted by its weight w to the position shown in. full lines, thus pulling up the link 3' and arm and causing the pawl Z to advance the ratchetwheel m the distance of one tooth. The consequent turning of the arbor J winds up the spring E to the corresponding extent.

The proportions of the respective parts are such that by the action of the pawl and ratchet the spring K is wound up at each excitation of the magnet as much as it has run down by the rotation of the gear L in turning the pinion n and seconds-arbor one revolution. Thus at the end of each minute the spring is wound up as much as it has run down during such minute, so that it is restored to its original tension. The winding up oi"; the spring K is effected directlyby the tension of the counterweight w when this counterweight is released by the reaction of the armature, so that the tension applied to the ratchet and pawl is always uniform and independent of the strength of the battery, so that no possible derangement can result from the varying energy with which the magnet may be excited at different times.

I will now explain how the dial mechanism shown in Fig. 2 is driven. The lever S carries an arm or finger to, which, upon the release of the armature and the return of the lever by the action of the counterweight, moves down against the bearing-face Ct on a lever G, thereby tilting this lever and causing a pawl G, which it carries, to strike one of the teeth of a ratchet-wheel A, fixed to the spindle of the disk A, and turn the latter one-tenth of a revolution. Before turning it, however, the pawl G acts on the inclined end or toe (Z of an elbow-lever e, the other arm of which carries a locking-tooth H. The pawl acts first to press back the toe (Z, thereby lifting the lock 11 out of one of the notches in a locking-disk H to the position shown in full lines in Fig. 8. It then holds the levcre and lock II in this position while it turns the ratchet-wheel A and until it reaches the position shown in dotted lines in Fig. 8, the notch having thus been moved beyond the bolt to the position shown at c, whereupon the pawl releases the toe and permits the lock to drop onto the disk ll, ready to fall into the next notch, and the pawl continues to move down until it reaches the position shown in dotted lines in Fig. 2, having thus advanced the ratchet A the distance of one tooth. At the completion of an entire revolution of the disk A, that is to say while it is turning from 9 to 0, an armf, which it carries, encounters a pin or projectionf, iixcd to and projecting rcarwardly from the disk 13, and turns the latter one space, so as to cause it to display the next higher number. First, however, the disk 13 is unlocked by releasing a lock B, having a notch which engages one of the pins f" thereof. This lock 13 is carried on a lever g, which is tilted by the action of a pin 9, carried by the disk H on a tooth 9 connected through a rod g with the lever 9. As the disk B turns from 5 to blank (or zero) an arm 71,, which it carries, strikes a pin f on a disk 0, fixed on the arbor of the disk 0, and turns the latter onetwelfth of a revolution. First, however, the disk 0 is unlocked by withdrawing a lock C, which engages one of the pins f thereof. This lock 0 is mounted on a lever g", which is tilted by a pin g carried with the disk B, acting on a tooth g on a rod 9 connected to this lever.

\Vhen a clock has both the numbered disks A, B, and C and the dial D with its hands,

the latter are turned by the mechanism shown in the upper part of Fig. 2. A rod t', pivoted to the lever G at its lower end, communicates motion to a smaller lever V above. The pawl V of this lever acts in the teeth of a ratchet-wheel W, fixed on the minute-hand arbor. A notched disk Y, also fixed on this arbor, is locked by a lock Y, mounted on an elbow-lever e, the lower arm of which has a cam surface or toe d, which is displaced by the end of the pawl V before it commences to move the wheel WV. The operation is the same as the lock 1-1 with the disk 11, already described. The motion is communicated to the hour-hand through the usual wheels y y.

In lieu of operating the ratchet m by a pawl Z on an arm k, as shown in Fig. 3, I prefer to employ the construction shown in Figs. 5, 6, and 7. The ratchet m has peripheral teeth engaged by the locking-pawl Z, and in addition is formed with crown ratchet-teeth m, which are engaged by similar crown ratchetteeth m formed on a disk Z pivoted on the arbor J, and pressed toward the ratchet m by a leaf-spring t". The disk Z is oscillated forward and back by the rod j, which is connected to an arm it, formed on this disk. As the arm is moved upwardly the teeth 'm propel the ratchet m forward, and as the arm is moved downwardly the teeth m ride over the teeth m, the spring t" pressing them backwardly into engagement with the next successive teeth. The disk Z with its teeth m constitutes, substantially, a pawl.

By my improved construction of clock the time-measuring mechanism is reduced to the utmost simplicity, consisting only of the escapement, its impellin g-spring, and their connecting-gear and pinion. The liability of derangement is consequently reduced to the minimum, so that with proper workmanship the clock should run for years without attention. So long as the mechanism remains in order the clock will continue to run as long as the battery supplies the necessary energy. By reason of the very frequent rewinding of the spring K it is kept always at uniform tension, so that the impulse of the escapement on the balance-wheel is unvarying. The energy required to be transmitted through the spring is reduced to the minimum, so that a light spring may be used. The electromagnet at each operation thus stores up the power required for driving the time-measuring mechanism by which it is governed, and also exerts the power necessary to drive the time-indicating mechanism. The time-measuring mechanism is thus entirely relieved of the work of driving the time-indicatin g mechanism, so that the clock is rendered a very accurate timekeeper. This subdivision of the work is especially desirable in a clock wherein the time-indicating device consists of a combination of dials, since the driving of such device requires different amounts of power at different times, requiring the least power when only the disk A is being driven,- requiring greater power when the disks A and B turn simultaneously, and still greater power at intervals of an hour, when the disks A, B, and 0 turn all together.

By the construction of the magnetic winding apparatus with an armature-lever M, with its long arm bearing on the long arm of a counterweighted lever S, and the latter connected to a swinging arm for moving the pawl Z or Z a long sweep is secured, and the pawl enabled to propel the ratchet far enough at each vibration to wind up the spring sufficiently so that only a single gear and pinion is required to communicate movement to the seconds-arbor, and the latter is propelled for an entire revolution before the spring requires rewinding. Otherwise it would be necessary to close the circuit oftener than once a minute, or to interpose more wheels to gear up sufficiently to the seconds-arbor.

My improved clock may be used as a primary electric clock for controlling the move ments of secondary electric clocks. This may be done, as shown in Fig. 10, where the lever S is connected in the circuit 1) of a battery F and at each Vibration makes contact with levers h h, thereby closing circuits q q, leading to distant secondary clocks X X. These secondary clocks are of any usual construction. When the lever S vibrates back to its normal position, the contact-levers h h are drawn by their springsrragainst screw-stops u a. By adding more levers h h the same clock may be used to operate a greater number of circuits, or additional secondary clocks may be introduced in the same circuits q q.

My improved electric clock may be used as a secondary clock by omittingthe time-measuring mechanism, including the escapement and escapement-spring and the means for winding the latter, and by connecting the electromagnet M in circuit with a primary clock which'shall close the circuit once a minute or at other intervals. The lever S then acts through the arm a upon the lever G only to operate the time-indicating mechanism.

I claim as my invention the following defined novel features or improvements, substantially as hereinbefore specified, namely:

1. In an electric clock, wherein the escapement-spring is wound by an electromagnet, said spring and said magnetin combination with a lever S tilted by said magnet, a rod j connected thereto, a vibrating arm is connected to said rod, an arbor connected to said spring for winding it, a ratchet m on said arbor,havin g peripheral teeth and having crown ratchet-teeth m, a pawl Z fulcrnined on said arbor, operated by said arm is, and having crown ratchet-teeth m engaging the teeth m of said ratchet, a locking-pawl Z engaging the peripheral teeth of said ratchet, and a spring pressing said ratchet andpawl into engagement, substantially as and for the purpose set forth.

2. In an electric clock the combination with aloek H, of a disk ll looked thereby, a lever e operating said disk and having an inclined toe d, a pawl Gr acting" to press said toe to one side, an operating-arm G carrying said pawl and a ratchet-Wheel A actuating a time-indicating device and controlled by said pawl, substantially as and for the purpose set 10 forth.

In Witness whereof Ihave hereunto signed my name in the presence of two subscribing Witnesses.

EMIL G. HAMMER.

\Vitnesses:

ALFRED BoWERs, GEORGE II. FRASER. 

